Many New Drugs Have Side Effects

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Many New Drugs Have Side Effects

Tue Apr 30, 9:55 PM ET

By LINDSEY TANNER, AP Medical Writer

CHICAGO (AP) -

One in five new drugs has serious side effects that do not show up until

well after the medicine has received government approval, according to a

study that exposes what one researcher calls an alarming game of medical

Russian roulette.

The researchers went so far as to suggest that doctors should prescribe

older drugs when possible, unless the new one is truly superior.

" It's like playing Russian roulette when a doctor prescribes a newly

approved drug that doesn't have a big breakthrough, " said Dr. Sidney

Wolfe of Public Citizen Health Research Group, one of the researchers

who worked on the study.

Pressure from pharmaceutical companies and doctors' failure to closely

read warning labels are partly to blame, the researchers said. They said

the findings should prompt the Food and Drug Administration (news - web

sites) to consider raising its threshold for approving new drugs when

safe and effective alternatives exist.

The findings are based on an analysis of 548 drugs approved from 1975

through 1999. Of these, 56, or more than 10 percent, were later given a

serious-side-effect warning or taken off the market for safety reasons.

The number climbed to approximately 20 percent when researchers took

into account drugs that were approved toward the end of the period

studied.

The study, led by Dr. Lasser of Cambridge Hospital and Harvard

Medical School (news - web sites), appears in Wednesday's Journal of the

American Medical Association (news - web sites).

An accompanying editorial by two FDA experts said the analysis

overstates the problem.

Safety studies that are conducted before a drug wins approval typically

involve a few thousand patients and may not detect all side effects,

especially relatively rare ones, Drs. Temple and Himmel

said.

" Frequent post-marketing label changes are therefore inevitable and

should be anticipated, " they wrote.

Temple also noted that some medications cause side effects in only

certain groups of patients, such as pregnant women, which does not mean

a drug is dangerous for everyone.

The study analyzed what are known as " black-box " warnings published in

the Physicians Desk Reference, a compendium of drugs and labeling

information published annually. Black-box warnings highlight the most

serious side effects.

Sixteen drugs studied were withdrawn from the market, nearly half of

them more than two years after they had won approval.

They include the diabetes drug Rezulin, which was approved in 1997 but

has been linked to dozens of cases of fatal liver damage. Lasser said

doctors continued to prescribe it an unsafe manner even after it was

given a black-box warning, and it was ultimately withdrawn from the

market in 2000.

Two allergy drugs, Seldane and Hismanal, were linked with potentially

fatal heart problems in certain patients but were not removed from the

market until several years after receiving black-box warnings.

Most troublesome new drugs do not represent any advance in treatment and

are at best no better than older, safer drugs already on the market,

Wolfe said.

Unless a new drug is a breakthrough, it should be avoided until its

safety record is better known, the researchers said.

" When a drug that comes on the market has a 1-in-5 chance that it's

going to have to be banned or get a black-box warning is pretty

worrisome, " Wolfe said.

He said the FDA is correct in saying doctors do not pay enough attention

to warning labels, but that is " all the more reason to do the right

thing on the front end. The remedy should be don't put the drug on the

market unless it's a breakthrough drug. "

The FDA has said that while its drug review process has gotten shorter

in recent years, the procedure is still adequate. But the agency has

expressed concern over doctors not reading drug warning labels closely.

Temple said that while doctors are getting better at reporting side

effects to the FDA and drug companies, the agency is seeking further

improvements, including a proposal to include a drug's approval date on

packaging inserts.

" I don't think anybody believes that we're absolutely at the best we can

do, but it's better, " Temple said.